Metal-tube machine.



L. E. HOOKER.

METAL TUBE MACHINE.

APPLICATION rum) APB.17, 1908.

Patentfad Apr. 1;3, 1909. I

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Witnesses ggg; w %W (L. E. HOOKER.

METAL TUBE MACHINE.

APPLICATION FILED APR. 17,1908.

918,154. Patented 13, 1909.

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amnntoz LESLIE E. HOOKER, OF PAWTUGKET, RHODE ISLAND.

METAL-TUBE MACHINE.

Application filed April i7, 1908. Serial No. 427,591.

To all whom it may concern:

Be it known that I, LESLIE E. HooKnR, acitizen of the United States,residing at Pawtucket, in the county of Providence and State of RhodeIsland, have invented certain new and useful Improvements in Metal-TubeMachines, of which the following is a specification.

My invention relates to the manufacture of tubes by the method disclosedin the patent to G. W. Lee issued Julie 5th, 1906, No. 822,285, andconsists in certain improvements which I have made in the construc tionof the apparatus by which said method is carried out. 1 I have found byexperiment that much stronger tubes can be made by starting theextrusion with a cup-shaped blank formed by folding up the edges of adisk around a punch or mandrel than when starting with a disk, 'asdescribed in the above mentioned patent, but, when working with a hardmetal, such as brass, the strains upon the dies and punches, are sogreat as to cause frequent breakage.

The improved construction of these, hereinafter described, removespractically all danger of breakage, and enables tubes to be madesuitable for cartridge shells, which are v stronger and lighter thanthose made by the present process of drawing. So that, my presentinvention consists in certain im rovements in the construction of thedies in which the blanks are placed to be extruded into tubes, in theprovision of mechanism for detaching and removing the flange scrap fromthe tubes and dies; in improvements in the construction of the formingand extruding punch, and, finally, in the combination and arrangement ofthe arts going to make up a practical and e cient machine for carryingout the, process.

In the accompanying drawings, Figure 1 is a central longitudinal sectionthrougl'f'the dies and the punch-carrying slide of a press equipped withmy improvements, Fig. 2 is a plan view of the tube-retaining means toprevent their withdrawal from the dies with the forming unch, Fig. 3 isan enlarged section of a b ank to be operated upon, Fig. .1: is across-section ofFig. 1, taken on the line of said figure, and Fig. 5 isa. sectional view of a modified form of the punch holder. I

Any suitable form of press maybe used, that illustrated being by way ofexample Specification of Letters Patent.

Patented April 13, 1909.

. only. On top of the apertured bed-plate 1 of the press is bolted aplate 2, in which are inserted two hardened plugs 3, 3, which arecentrally bored and lie directly beneath the dies 4, 1. The'dies areheld in aplate 5, which is shrunk onto them, thus constituting asustaining jacket for the same, said plate 5 being bolted down onto theplate 2. The dies have each a central aperture, of substantially equaldiameter with the blanks, in which is placed a hardened bushing 6, theupper end of which slopes slightly inwardly toward the central aperture7, as shown. This bushing constitutes one of the most essential featureswhich renders,the present a paratus so cilicient and practical. Heretoore, in carrying out the process of the said patent thc'die was madeintegral and it would not last when working on hard metal, such as coper, for example In the present construction, the bushing has merely adriving fit in the die and rests on thehardened plug 3, which takes thedownward strain-instead of the die,

which is subjected to a radially outward strain only. It is essentialthat the bushing 6 should pass entirely through the die 4 and rest uponthe hardened plug 3, as practice has demonstrated that when the bushingis sustained by a shoulder within the die, breakage always occurs atthat oint. In this connection I may say that t e construction of diejust described is useful wherever a drawing operation is used and Itherefore do not wish to be understood as limitin my invention in thisrespect to use in extru ing presses.

In the machine herein illustrated, I have shown two dies, with whichcooperate, at each stroke of the press, one forming and extruding punch8 and one of two trimming punches 9, all three of which tools arecarried in the slide 10, mounted in a transverse guide of thereciprocating press-head 12.

The slide 10 is moved from one extreme position to the other by the handof the operator, or by any ordinary slide-moving mechanism, between eachstroke of-the press, adjustable stops 11 for said'slide being provided.Each trimming-punch is adjustablv threaded into a stem 13, set in theslide, and a similar stem 14 carriesthe forming and extruding punch. Inthe head 12 of the press are set two hardened plugs 15,.similar to theplugs 3- and directly above the same, pressure being exerted'throughthem to the punches. Obviously a rotary turret could be used instead ofthe slide.

die above described. The stem 14 has a countersunk central bore, asshown, in the lower end of which is fitted an anvil 16, above which, inthe smaller portion of the bore, is slidably mounted a nut 17. Into thislatter is adjustably threaded the central portion of the punch 18, whichI will designate as the former, a set-screw 19 being provided, ifdesired, to lock said former in adjusted position. To keep the nut 17from rotating when the former is adjusted, a setscrew 20 is, or may beprovided in the stem, the same engaging in a lateral slot in said nut.

Surrounding the lower part of the former 18, and clamped against theanvil 16 by the chuck 21, is the extruding plunger 22. It will thus beseen that the former can move relatively to the extruding plunger, bywhich construction important results are obtained. While the above isthe preferred construction, it is not absolutely essential that theformer should be capable of sliding longitudinally relatively to thelunger, although it is essential, for a practically eflicient machine,that it should be made separate therefrom. In other words, the formermay be threaded directly into the stem 14, as shown in Fig. 5. Eitherconstruction enables'me to make these punches of the requisite hardnesswithout incurrin danger of their breaking at the point of unction whichthey very soon did when made integral, owing to the tremendous strain,tending to pull the ,former .downwardlyand to force the plunger upwardlyWhile the tube was bein extruded, and the inelasticity of theintegraconstruction. The new constructions give elasticity to. the tool whichenables them to yield under the, strain and thus avoid breakage.

In, practice, it is usually necessary to pass the tubes through a straihtened die or through a shaping die, as w en they are to,

be finished hexagonal in cross-sectlon, for lnstance. There is, ofcourse, a

of the en shaped blank are increased'in height. T e former 18 isaccordingly adjusted downward in the stem, so that it will contact withthe bottom of the blank just be- As will be obvious, the amount ofmovement of the block ornut 17 in the stemmay be adjusted byincreasing'or diminish-- ing the length of said nut.

racticallimit to the diameter of the blanks -w ich can be extruded,underpresent conditions I find There remains to be described the constructionand operation of the trimmingpunches. The action of these is to push thetube away from the flange left on the top of .the bushing, and the onlyessential feature of their construction is that their diameter wherethey enter the dies must be intermediate the inside diameter oi thebushing and the inside diameter of the tube. Thus they tear the walls ofthe tube away from the liange, and as they go up again, the'fiange iscar ried with them, by reason 01 the contraction. of the metal onto thepunch and also of the dish-shaped form of the'lianges which, when theupward movement of the punch tends to straighten them out, causes themto bind on the punch. As shown, the punches are formed with heads 25,having shoulders at both ends, the smaller front end of the punchesserving as guides to center them in at the tubes, and the shoulders toact on the metal of the tube, one to sever and push away the wall fromthe flange and the other to engage the flange and with-draw it on theupward stroke, but this construction is not essential, it being onlynecessary that the diameter of. the trimming punch bear the relationstated to those of the bushing and tube, and that it be suiiicientlysolid or resistant to sever the metal. The scrap flanges may be strippedfrom the trimming punches, or allowed to collect thereon and besubsequently removed by unscrewing the punches from the stems 13. I

To prevent the tube from sticking to the former 18 as the latter risesfrom the die, 1 provide a spring clam 27 adjustably located below theplate 2, so as to grip the'end of the tube as it is extruded. Any formof clamp or catch may beused, that shown consisting of two semi-circularplates 27 having a conical. aperture .28 atjtheir center and with theirmeeting edges beveled. Screws 29 loosely and adjustablyfsecure theplates to the; platev 2 and screwsf30 in connection with a wire3ljpassing' around theperiphery of the clamp,i7 hold'fthe' platestogether.

Their action wiltybejjfobvious; they yield apart as the tubepassesdownbut are caused to bite the same when it starts to go up, thusreleasingit from the former.

Y The operation is as ,follows: A blank beingplaced in one ofthe dies,resting on the top of the bushing, the slide is moved so as to bring-thepunch 8 over said die and the press is started. The former 18 firststrikes 65 fore the extruding punch commences to actuplunger wereintegral, as previously eo'nent construction, the former is carrieddownward intov the throat of the *die by the metal as it is extruded atthe commencement of the operation, until the lower end of the nut 17strikes against the anvil 16, which also takes the upward pressureexerted by the plunnor-"22.

The threaded connection of the former with the nut provides a certainelasticity, and all danger of breakage of the former is obviated.Furthermore, another important result is obtained by permitting theformer to move downwardly at first into the die, which'is that theinterior of the closed end of the tube is perfectly finished in thisoperation, that is to say, a square vcorner is formed, whereas, when theformer was rigidly attached to the plunger, the metal would flow inaround the" end of the former leaving a round corner at the inside endof the tube, which had to be removed in the finishing operation or elsea greater length of the tube had to be sawed ofl". In the manufacture ofcartridgeshells, when the closed end of the tube forms the head of theshell, it is difiicult to square up the said round corner Withoutcausing cold-shuts'in the metal, fora great deal of pressure has to beexerted in the operation of shaping the head of the shell to get rid ofsaid round cornerywhereas all such difficulty is avoided when the corneris left square, as it is with the apparatus constructed as abovedescribed. 1

Having thus described my invention, what I claim is: a,

1.' Ina machine of the class described, the combination with the bedplate, of a perforated hardened plug held therein, a jacketed diesecured on said bed-plate and a bushing inserted in said die and restingon said' 2. In a press of the class described, the combination with thedie plate and the reciprocating head, of a punch carrier movable in saidhead, a forming and extruding punch and a trimming punch carriedin saidcarrier, whereby they are alternately brought into alinement with saiddie.

3. In a machine forforming tubes by extrusion, the combination with adie containing a bushin of less length than the thick- I ness of saiddie, of a support for said bushing underneath the die, a punchcomprising an extruding plun er of a diameter to fit the aperture insaid fie and a former of a diameter less than the inside diameter of sabushing, means to adjust said former relatively to said plunger andmeans to reciprocate said punc 4. In a machine for forming tubes byextrusion, the combination with the bed-plate and reciprocating head ofthe press, a plate secured to said bed-plate and containing a pair ofdies,oa carrier movably mounted in said head, and containing a formingand extruding punch and two trimming punches,

the diiferent positions of said carrier being adapted to cause saidforming'and extruding punch to, coact with one of said dies and to causeone of said trimming punches to coact with the other of said dies,whereby, at each reciprocation of said head, one tube is extruded from ablank another tube is separated from its scrap flange and'the latterremoved.

5. In a machine for forming tubes by extrusion, adie having'a centralaperture and a bushing therein, of a punch, comprising a former adaptedto enter said bushing and an extruding plunger of a diameter to fit theaperture in said die, and a trimming punch, the diameter of which isless than the internal diameter of said bushing and greater than thediameter of said former.

ing an internal shoulder, a punch having a central former of lessdiameter than the reduced portion of said aperture and an annularplunger fittingthe upper portion of said aperture, and a trimming punchthe diameter of which is intermediate that of said reduced portion andthat of said former.

7, A. machine for the purpose described, comprising in combination asupporting plate containing an apertured hardened plug, a die secured onsaid supporting plate and containing a bushing, the lower end of whichrests on said hardened plug, a reciprocating head containing a hardenedplug, a slide, containing a forming and extruding punch and a trimmingpunch, movable transversely in said head to bring said punchesalternately beneath said last mentionedplug and over said die, saidformingand extrudin punch comprising a central former of less iameterplate containing an apertured hardened plug,

a die secured on said supporting plate and containing a bushing, thelower end. of which rests on said hardened plug, a reciprocating headcontaining a hardened plug, a slide containing a forming and extrudingpunch and a trimming punch, movable transversely in said head to bringsaid punches alternately beneath said last mentioned plug and over saiddie, said forming and extruding punch comprising a central former ofless diameter than the aperture in said bushing and said trimming punchbeing of a diameter intermediate that of said former and that of theaperture in said bushing and diameter less than that of the aperture inthe die but greater than the internal diameter of the tube formed, andmeans to reciprocate said punch into said die.

10. In a. machine of the class described, the combination with the die,and the reciprocating press-head, of a stem carried by said head, and ananvil secured in the lower portion of said stem, a block slidablymounted in said stem above said anvil, a former adjustably secured insaid block, an extruding plunger surrounding the lower end of said.

former, and means to clamp said plunger against said anvil.

11. In a machine of the class described, the

combination with a die, of a reciprocatory head, a hollow stem securedtherein, an annular, plunger bearing against the end of said stem, meansto secure said plunger in position, and a central forming-punch passinthrou h said plunger and adjustably secured to sai stem.

12. In a machine of the class described, the combination with a. diecontaining a hardened bushing of less length than the thickness of saiddie, and an apertured hardened plug beneath said die and bushing tosupport the latter in place independently of the die, of a reciprocatinghead having rigidly secured thereto a hollow extendingfplunger of adiameter to fit said die, and a central forming punch of a diameter lessthan that of said bushing. and movably secured in said head.

13. In machine of the class described, the combination with a diecontaining a bushing of less length than the thickness of, said die,

'and a support for said bushing independent of said die, of areciprocatory head carrying an apertured extruding plunger, of adiameter to fit the aperture in said die, and a formin punch of adiameter less than the inside iameter of said bushing, and projectingcentrally through said plunger, but secured to said head independentlyof the same, and means to reciprocate said head.

In'testimony, whereof I have affixed my signature, in presence of twowitnesses.

LESLIE E; HOOKER.

